Ipod and phone

I am coming up to my build date for a 55 and I want to make sure I understand my options. I want to retrofit the Ipod cradle when it's available, do I need to do anything now or will this be a relatively easy dealer install later with all SLK's with command?
My other concern is about the phone option. I was not interested in the MB phone and contract but I love the integrated phone idea. Is it possible to add the option and then retrofit in another phone? If so how much trouble would it be???? Thanks,,Brad